The present invention disclosed herein relates to an apparatus for generating a proton beam, and more particularly, to a proton beam generation apparatus using a laser beam.
Proton ion beam treatments are in the spotlight as treatment methods which can mitigate side effects due to X-ray treatments or electron beam treatments. To allow a proton ion beam to penetrate a material, the proton ion beam should be accelerated to have high velocity, like electrons. Even though the proton ion beam gradually decreases in velocity when the proton ion beam penetrates a certain material, the proton ion beam is subject to the most energy loss of ionizing radiation just before the proton ion beam is stopped. This phenomenon is called a Bragg peak after William Henry Bragg who discovered the phenomenon in 1903.
Thus, when the velocity of proton ions are precisely controlled, malignant tumors may be selectively and locally treated. When tumors are disposed at a deep position of the human body, protons or ions should be accelerated to a significantly high energy level at the outside of the human body. Methods of accelerating protons or ions may include a laser driven ion acceleration method. When a high-power laser beam is emitted to a thin film target, ions or protons within a thin film escape with acceleration energy by a target normal sheath acceleration model (TNSA model) or a radiation pressure acceleration model (RPA model). A proton ion beam may penetrate the body of a patient according to energy of the proton ion beam and be stuck in the location of a tumor. The patient can be treated according to the principle that a large amount of free oxygen radicals are generated in a tumor portion near protons to necrotize tumor cells.
In the initial stage of the study, a proton beam could be obtained using a particle accelerator. Today, a proton beam can be obtained using a laser system that is superior to a particle accelerator in terms of spatial constrain. The laser system can generate a large amount of proton beam by using a high power laser beam. Thus, various types of research and development are being carried out in order to obtain a proton beam having a mono-energetic distribution.